Unsoundness in Iterator and DoubleEndedIterator impls for glib::VariantStrIter

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

The VariantStrIter::implget function (called internally by implementations of the Iterator and DoubleEndedIterator traits for this type) was unsound, resulting in undefined behaviour. An immutable reference &p to a mut libc::cchar pointer initialized to NULL was passed as an argument to a C function that that mutates the pointer behind &p in-place (i.e. as an out-argument), which was unsound. After changes in recent versions of the Rust compiler, these unsound writes through &p now seem to be completely disregarded when building the glib crate with optimizations. This subsequently caused all calls of VariantStrIter::implget to violate the safety requirements of the std::ffi::CStr::fromptr function - which requires its argument to be a valid pointer to a C-style string - resulting in crashes due to NULL pointer dereferences. This was fixed by passing the out-argument pointer explitly as &mut p instead of &p. This issue has been present since this code was initially added in glib…

Published by the source

23 Dec 2024, 20:19 UTC

Last modified by the source

23 Dec 2024, 20:19 UTC

Source last checked

26 Oct 2026, 15:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wrw7-89jp-8q8g

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-wrw7-89jp-8q8g

Advisory: Unsoundness in `Iterator` and `DoubleEndedIterator` impls for `glib::VariantStrIter`
IDs: GHSA-wrw7-89jp-8q8g
Record: https://patchnext.com/advisories/ghsa-wrw7-89jp-8q8g (revision 1, source checked 26 Oct 2026, 15:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: glib 0.20.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io glib: affected >= 0.15.0, < 0.20.0; fixed in 0.20.0

## Suggested inspection (read-only)
- crates.io glib: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on glib.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wrw7-89jp-8q8g (GitHub-reviewed advisory GHSA-wrw7-89jp-8q8g lists affected ranges: crates.io glib >=0.15.0 <0.20.0)

Commands are suggestions: review each one before running it.